Del Mar smell a mystery

The beach is full of strange smells sometimes — saltwater, sun-baked seaweed, musty sea floor on a low tide — but something smelled different Tuesday.

Beachgoers and lifeguards noted a peculiar aroma in the late afternoon and early evening. Some accounts said around 3 p.m., others closer to 5 p.m. Unlike the fishy stench typical at the beach, the scent wafting over the ocean Tuesday had hints of gas.

“It smelled like gas from the stove, or propane,” said Lauren Humann, a Del Mar lifeguard who noticed the smell when she was paddling around on a longboard Tuesday afternoon. “It was not pleasant at all. It was almost toxic, it seemed like.”

Humann said she and a friend only detected the smell while out on the water.

The San Diego Air County Pollution Control District looked into it. Upon hearing reports of the funk, they sent an investigator, who couldn’t detect anything.

Rob Reider, spokesman for the district, said there were light winds, about 5 to 6 mph out of the northwest, at the time the smell was noticed, but that the agency can do little if they can’t find the odor.

Graduate students at the Scripps Institution of Oceanography appeared to have found evidence of a methane gas leak from an underwater earthquake fault about 20 miles off Del Mar. Methane is odorless, and likely isn’t related to the smell beachgoers picked up Tuesday.

County officials said they considered a possible link.

“The thought has occurred that that might be connected,” Reider said. “It doesn’t appear to be linked. Unfortunately the cause still remains elusive.”

A mystery odor reportedly floated over San Diego County in August of last year. It was also described as smelling like fuel, and was first detected in North County, including Del Mar. It was noticed in the afternoon and was eventually noted by people in University City, Scripps Ranch, La Jolla, Pacific Beach, Hillcrest and downtown San Diego.

The source of that smell was never determined, Reider said.

“We took numerous samples throughout various places and the air samples turned out to be just normal,” Reider said. “It certainly covered some of the same area. ... It continues to be a mystery for us here.”